WO 2003/030247 A2 describes a method for making planar contact with electrical contact surfaces of a substrate, and a device including a substrate having electrical contact surfaces. In the procedure for making contact with electrical contact surfaces on a surface of a substrate, a polyamide-based or epoxy-based film is laminated onto the surface under vacuum, so that the film closely covers the contact surfaces and adheres to this surface, each contact surface for making contact on the surface is exposed by opening respective windows in the film, and planar contact is made between each exposed contact surface and a metal layer. In particular, power semiconductor chips, which need a high current density and have large surface-area contacts, are devices produced in this manner.
This method is used to produce planar electrical contacts, i.e. contacts that extend over a two-dimensional area, with three-dimensional components. Large contact windows in relatively thick insulating materials need to be opened for the required openings in the insulating layers. The thickness of the insulating materials usually lies in the region of 200 μm. The openings in the insulating layers are used in particular for making through-connections to substrate and chip contact-surfaces. Contact windows are conventionally opened by means of laser ablation patterning over the entire surface, with an area of about one cm2 conventionally taking about 100 seconds to open. This results in undesirably long processing times and is hence economically disadvantageous in a scheduled fabrication process.